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Dental CrownNCT02609178

Basic Study of Fabricating Biomorphic Crowns

A study testing FGP and AVR in people with Dental Crown and Prosthesis, run by Air Force Military Medical University, China at 1 site in China.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The purpose of this study is to compare among different designs of the occlusal surface of artificial crowns, trying to determine a guidance of fabricating artificial crowns with better mimesis of the original tooth crown in terms of morphology. Read more about this study

Who is it for?
Ages 18 to 65 yearsHealthy volunteers can take part
Conditions the study is for
Dental Crown, Prosthesis
What is being tested?
FGP and AVR
Type of treatment
Surgery or procedure
Could I receive a placebo?
No, everyone receives an active treatment
How many people
12 participants
Where
1 siteChina
Study dates
Dec 2015to Mar 2016
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 65 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • single crown restoration needed in posterior quadrants
  • the antagonist of the abutment tooth is purely natural or received minimum restorations that does not change its morphology too much
  • no orthodontic treatment history
  • stable occlusion
  • no parafunctional movements existed

Who cannot join

  • sequential crown restorations needed
  • the morphology of the antagonist of the abutment tooth has been largely changed by previous treatment
  • no contact exists between the abutment tooth and its antagonist
  • orthodontic treatment history
  • unstable occlusion
  • existed parafunctional movements
  • participated in other clinical studies

Trial locations and contacts

1 site in 1 country.

China1 site
  • Stomatological Hospital of Fourth Military Medical University

    Xi’an, Shanxi, 710032

Other trials in China

About this study

Official title: Comparative Evaluation of Different Occlusal Surface Designs of Artificial Crown

The purpose of this study is to compare among different designs of the occlusal surface of artificial crowns, trying to determine a guidance of fabricating artificial crowns with better mimesis of the original tooth crown in terms of morphology.

Read the detailed description

For occlusal surface design, each subject would be given 3 crowns using different fabricating guidance -- the FGP technique(FGP),the average setting technique(AVR) and conventional technique(CON), separately. Upon baseline visit, general tooth preparation procedures would be performed, including impression taking before and after treatment and tooth preparation. Sometimes photo taking is needed. On try-in visit, subjects would be ask to fill in questionaires(Likert's scale) and the adjusting time for each crown would be recorded. Moreover, t-scan would be used to assess the occlusal equilibrium. All in all, including adjusting visit for FGP, the subjects have to visit the clinic for 3 times which would take them 3-week time.

The Institutional Board(IRB) of the Stomatological Hospital of Fourth Military Medical University(FMMU) would be in supervision of the whole study and is responsible for the quality assurance plan, data check and source data verification.

Subject recruitment would done within those patients visit the department of prosthodontics of the Stomatological Hospital of FMMU and have an interest towards this study. One clinician would be appointed to enroll the subjects according to the standards. To avoid errors, all the examinations done in the study shall be accomplished by the same clinician and the crowns fabricated in the study shall be designed by the same technician. The clinician and the technician participated would receive adequate training before the study to ensure their performance. Every subject in the study should assign informed consents at the beginning of the study and establish case report forms(CRFs). During the study, if adverse events(such as crown chipping, crown dropping or iatrogenic gingivitis, etc) happen, subjects are required to contact the investigator within 24 hours; and the investigator should then report to the IRB within 24 hours. Following treatment or compensation would be done according to the clauses stated in the informed consent signed by the subjects.

The whole study needs subjects in total. During the study, subjects have their own right to quit the study at any time if they have discussed with the investigator in advance. These subjects then are deemed as "unavailable". If subjects don't contact the investigator and quit the study(the investigators can't contact them within the follow-up period), their records then are deemed as "missing".

All the information collected in the study would be protected and only be used within this study. The statistical analysis of this study would be processed with the aid of the department of statistics of FMMU.

Being tested
FGP, AVR
Keywords
artificial crown, biomorphic, functional generated path, muscle-action theory, anatomic theory

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • FGPProcedure or surgery

    Also called general

    To execute FGP technique, the occlusal surface of the interim should be back cut to leave at least 1mm occlusal space. Then apply the recording resin. Ask the subjects to close the mouth to maximum intercuspal position then perform right lateral, left lateral and protrusive movements in succession ending in maximum intercuspation position. Excessive resin then should be trimmed off and Bausch articulating paper would be used to mark the intercuspal contacts. Zinc oxide is then applied to check eccentric occlusion, trimmed off resin if there're interferences. Then the interim would be used as a copy to design the occlusal surface of the crown. (CAD/CAM)

  • AVRProcedure or surgery

    Also called average value

    the crowns in this group would be designed by setting virtual articulator to average mode (CAD/CAM)

Study groups in NCT02609178
Study groupRoleWhat they receive
FGP design (FGP, AVR)Experimentaluse functional generated path to execute different occlusal surface designs of the artificial crown and evaluate its efficacy
Receives: Procedure: FGP; Procedure: AVR
conventional design (CON)No interventionuse conventional method to execute different occlusal surface designs of the artificial crown and evaluate its efficacy

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. △OT Value

    Occlusion time (OT) is defined as the time from the first contact of occluding teeth to maximum intercuspation. OT is directly related with patients' occlusal contact pattern; and some have considered it as a capable description of occlusion.

    In the study, the OT value of each crown would be assessed before try-in (baseline) and immediately after try-in using T-scan (FGP, AVR, CON). Try-in procedure would be finished by the same clinician.

    △OT was calculated for minimizing individual difference among participants. The equation for △OT was:△OT(FGP/ AVR/ CON)= OT (FGP/ AVR/ CON)-OT(baseline)

    Measured: 2 weeks(plus or minus 7 days) after tooth preparation

  2. △DT Value

    Disocclusion time (DT) is defined as the time from maximum intercuspation to complete disocclusion during lateral movement. DT related tooth contacts with muscle activity. Abnormities in DT would result in change of muscle activity, thus facilitate the occurrence of temporomandibular joint disorders.

    In the study, the DT value of each crown would be assessed before try-in (baseline) and immediately after try-in using T-scan (FGP, AVR, CON). Try-in procedure would be finished by the same clinician.

    △DT was calculated for minimizing individual difference among participants. The equation for △DT was: △DT(FGP/ AVR/ CON)= DT (FGP/ AVR/ CON)-DT(baseline)

    Measured: 2 weeks(plus or minus 7 days) after tooth preparation

Secondary outcomes (2)
  1. Occlusal Adjusting Time for Crowns

    Try-in procedure would be finished by the same clinician. The occlusal adjusting time would be counted using a timer and recorded.

    Measured: 2 weeks(plus or minus 7 days) after tooth preparation

  2. Likert's Scale

    The questionaire was designed to evaluate participants' feeling towards the occlusal interference. It would be given to the subject after immediately try-in the crowns. In the questionaire:

    Score 0 = No interference (feel comfortable while biting on the artificial crown) Score 1 = Moderate interference(could feel the artificial crown is higher when biting on the artificial crown, but when firmly clenched, the upper teeth could bite on the lower ones) Score 2 = High interference(the artificial teeth is higher that the upper teeth couldn't bite on all the lower teeth when firmly clenched)

    Measured: 2 weeks(plus or minus 7 days) after tooth preparation

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted20 Nov 2015 (estimated)
  2. Study startDec 2015
  3. Primary completionMar 2016
  4. Study completionMar 2016

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Crossover
Masking
Single blind
Who is masked
Participant
Enrolment
12 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02609178
Sponsor's protocol ID
IRB-REV-2015039
Status last verified
Jun 2016
First submitted
16 Nov 2015
Last updated
2 Aug 2016
Data monitoring committee
Yes
Individual data sharing
Undecided

Publications

  • Mehl A. A new concept for the integration of dynamic occlusion in the digital construction process. Int J Comput Dent. 2012;15(2):109-23. English, German.

    PubMed 22891415
  • Ikeda A, Miura H, Okada D, Tokuda A, Shinogaya T. The effect of occlusal contacts on adjacent tooth. J Med Dent Sci. 2005 Dec;52(4):195-202.

    PubMed 16669453
  • Alhouri N, Watts DC, McCord JF, Smith PW. Mathematical analysis of tooth and restoration contour using image analysis. Dent Mater. 2004 Nov;20(9):893-9. doi: 10.1016/j.dental.2004.06.003.

    PubMed 15451245
  • Vasconcelos FS, Neves AC, Silva-Concilio LR, Cunha LG, Rode Sde M. Influence of anatomic reference on the buccal contour of prosthetic crowns. Braz Oral Res. 2009 Jul-Sep;23(3):230-5. doi: 10.1590/s1806-83242009000300002.

    PubMed 19893955
  • Kohal RJ, Gerds T, Strub JR. Effect of different crown contours on periodontal health in dogs. Clinical results. J Dent. 2003 Aug;31(6):407-13. doi: 10.1016/s0300-5712(03)00070-8.

    PubMed 12878023
  • Takada J, Ono T, Miyamoto JJ, Yokota T, Moriyama K. Association between intraoral pressure and molar position and inclination in subjects with facial asymmetry. Eur J Orthod. 2011 Jun;33(3):243-9. doi: 10.1093/ejo/cjq060. Epub 2010 Sep 9.

    PubMed 20829312
  • Olthoff L, Meijer I, de Ruiter W, Bosman F, van der Zel J. Effect of virtual articulator settings on occlusal morphology of CAD/CAM restorations. Int J Comput Dent. 2007 Apr;10(2):171-85. English, German.

    PubMed 17899892
  • Memon S. A Comparative Evaluation of the Effect of Double Casting Technique Using Functionally Generated Path and Conventional Single Casting with Respect to Functional Articulation, Patient Satisfaction and Chair Side Time, in Single Unit Molar Teeth: An In Vivo Study. J Indian Prosthodont Soc. 2014 Dec;14(Suppl 1):119-25. doi: 10.1007/s13191-014-0379-6. Epub 2014 Jul 10.

    PubMed 26199501
  • Curtis SR. Functionally generated paths for ceramometal restorations. J Prosthet Dent. 1999 Jan;81(1):33-6. doi: 10.1016/s0022-3913(99)70232-5.

    PubMed 9878972
  • Wiklund L, Rossi F, Strata P, van der Want JJ. The rat olivocerebellar system visualized in detail with anterograde PHA-L tracing technique, and sprouting of climbing fibers demonstrated after subtotal olivary lesions. Eur J Morphol. 1990;28(2-4):256-67.

    PubMed 2245134
  • Ender A, Mormann WH, Mehl A. Efficiency of a mathematical model in generating CAD/CAM-partial crowns with natural tooth morphology. Clin Oral Investig. 2011 Apr;15(2):283-9. doi: 10.1007/s00784-010-0384-z. Epub 2010 Feb 9.

    PubMed 20143242
  • Becker CM, Kaldahl WB. Current theories of crown contour, margin placement, and pontic design. 1981. J Prosthet Dent. 2005 Feb;93(2):107-15. doi: 10.1016/j.prosdent.2004.11.005. No abstract available.

    PubMed 15674218
  • Hazen SP, Osborne JW. Relationship of operative dentistry to periodontal health. Dent Clin North Am. 1967 Mar:245-54. No abstract available.

    PubMed 5225601
  • Yuodelis RA, Weaver JD, Sapkos S. Facial and lingual contours of artificial complete crown restorations and their effects on the periodontium. J Prosthet Dent. 1973 Jan;29(1):61-6. doi: 10.1016/0022-3913(73)90140-6. No abstract available.

    PubMed 4564800
  • Koidis PT, Burch JG, Melfi RC. Clinical crown contours: contemporary view. J Am Dent Assoc. 1987 Jun;114(6):792-5. doi: 10.14219/jada.archive.1987.0189.

    PubMed 3301975

Questions about this trial

What is this clinical trial studying?

A study testing FGP and AVR in people with Dental Crown and Prosthesis, run by Air Force Military Medical University, China at 1 site in China.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 2 Aug 2016. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 2 Aug 2016). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

△OT Value (time frame: 2 weeks(plus or minus 7 days) after tooth preparation). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02609178, which also lists 17 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Aug 2016.

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